PINACEAE 



The Larches 

 Characteristics of the Genus Larix Mill. 



HABIT. Tall, pyramidal trees; open crowns, with slender, 

 irregularly disposed, horizontal or pendulous branches; dwarfed, 

 short, spurlike lateral branchlets. 



LEAVES. Deciduous, needle-shaped or linear; produced in 

 dense false whorls or clusters on spurlike lateral branches; soli- 

 tary and spirally arranged on new shoots; numerous lines of 

 stomata on all surfaces; 2 resin canals in cross section. 



FLOWERS. Monoecious, terminal, single, appearing with 

 leaves; male naked, globose to oblong, consisting of several 

 yellow, spirally arranged scales, each bearing two pollen sac; 

 female erect, consisting of few or. many rounded, red-purple 

 scales in the axes of much longer scarlet bracts, each scale bearing 

 2 small inverted ovules. 



FRUIT. Woody, erect, short-stalked cones; maturing in one 

 season; cone scales thin, persistent, concave, longer or shorter 

 than their long-pointed bracts. Seed: 2 under each scale; triangu- 

 lar and light brown; large terminal wing. 



TWIGS. Smooth and glaucous, or hairy. Winter buds: sub- 

 globose, small, nonresinous, with accrescent inner scales which 

 mark lateral spur branches with prominent ringlike scars. 



WOOD. Rather strong and durable; small, scattered resin 

 ducts; thin, white sapwood and sharply defined, red to russet- 

 brown heartwood. 



SILVICAL CHARACTERS. Intolerant, slow-growing, and 

 found on a variety of habitats; extensive forests occasionally 

 destroyed by larch sawfly {Nematus erichsonii) . 



GENERAL. This genus contains about 10 species scattered 

 through the Northern Hemisphere. In North America 3 species 

 are native. The European larch {Larix decidua Mill.), an im- 

 portant tree, has been planted in the United States for ornamental 

 purposes. It can be identified by its puberulous cones, Y^-lVz 

 inches long, with inserted bracts and 40-50 suborbicular scales. 



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